near-fault ground motions have caused very much damage in the vicinity of seismic sources during recent earthquakes. it is well known that under specific circumstances, intensive ground shakings near fault ruptures may be characterized by short-duration impulsive motions. this pulse-type motion is generally particular to the forward direction, where the fault rupture propagates towards the site...

The decoherent (consistent) histories formalism has been proposed as a means of eliminating measurements as a fundamental concept in quantum mechanics. In this formalism, probabilities can be assigned to any description which satisfies a particular consistency condition. The formalism, however, admits incompatible descriptions which cannot be combined, unlike classical physics. This seems to le...

A major problem in the consistent-histories approach to quantum theory is contending with the potentially large number of consistent sets of history propositions. One possibility is to find a scheme in which a unique set is selected in some way. However, in this paper we consider the alternative approach in which all consistent sets are kept, leading to a type of ‘many world-views’ picture of t...

The possibility that quantum mechanics itself could be non-linear has run up against difficulties with relativistic covariance. Most of the schemes proposed up to now engender superluminal communication, and those that don’t, have been equivalent to linear theories. We show in a simplified model that a proposal based on the consistent histories approach to quantum mechanics avoids the usual dif...